Lexus RX 300 Engine Revs Up

The Car Began******** Like I Had Air In The Gas When I Accelerated, Then It Got Worse And The Rpms Would Fluctuate From High To Back Down...

When I Started The Engine And Moved Gear Change In 'r' Position I Felt Kind Of A Wince. Then I Drove Backwards, Stopped And Changed...

So My Rpm Is Between 3 And 4 After I Hit At Least 40 Mph...you Can Slightly Hear The Revving. What Could Be Wrong?